1. Field of the Invention
The present invention relates to a display system, and more particularly, to a laser display system using a laser as a light source.
2. Discussion of the Related Art
In the past, a projection display system uses a lamp as a light source. However, a laser display system using a laser instead of the lamp has been developed recently. Hereinafter, the display system will be described with reference to the accompanying drawings.
FIG. 1 is a detailed view illustrating a related art projection display system.
As shown in FIG. 1, the related art projection display system includes a lamp 110 generating light, a reflector 120 concentrating the light at one direction, a display panel 130 generating an image by modulating transmittance of light from the reflector according to a video signal, a projector 140 enlarging and projecting the image, and a screen 150 displaying the enlarged image.
The related art projection display system is operated as follows.
First, when the light is generated in the lamp 110, the light is concentrated at one direction in the reflector 120. In this state, the display panel 130 controls the amount of the light concentrated at one direction. At this time, the display panel 130 is usually formed of a liquid crystal display (LCD). After that, the image generated in the display panel 130 is enlarged in the projector 140, and the enlarged image is displayed on the screen 150.
FIG. 2 is a structure view illustrating a related art laser display system.
As shown in FIG. 2, the projection display system includes a laser 210 generating light, a illuminating device 220 irradiating the light to a display panel, the display panel 230 generating an image by modulating transmittance of the light illuminated from the illuminating device 220 according to a video signal, a projector 240 enlarging and projecting the image, and a screen 250 displaying the enlarged image. The related art laser display system has no big difference from the projection display system. However, the related art laser display system uses the laser 210 as light source, whereby the image displayed on the screen 250 has high resolution and high contrast ratio.
FIG. 3 is a structure view illustrating another laser display system according to the related art.
As shown in FIG. 3, the laser display system includes a laser 310 generating light, a concentrator 320 concentrating the light, an acousto-optic modulator AOM 330 modulating transmittance of the light from the concentrator 320 according to a video signal, a polygon mirror 340 obtaining a horizontal image of the video signal by rotating and reflecting the light transmitted from the AOM 330, a galvanometer 350 obtaining a vertical image of the video signal by repeating the light progressed from the polygon mirror 340 at a predetermined angle in up and down directions, and a screen 360 displaying the image obtained in the polygon mirror 340 and the galvanometer 350.
An operation of the laser display system according to the related art will be described as follows.
First, the laser 310 generates light, and the concentrator 320 concentrates the light at one direction. Then, the AOM 330 controls transmittance of the light concentrated according to an electric signal connected with the video signal.
After that, the polygon mirror 340 obtains the horizontal image of the video signal by rotating and repeating the light, and the galvanometer 350 obtains the vertical image of the video signal by repeating the light at the predetermined angle in up and down directions. Accordingly, the screen 360 displays the completed image:
The laser display system displays the image having high resolution, wide color resolution range and high contrast ratio.
However, the laser display system according to the related art has the following disadvantages.
In the laser display system according to the related art, speckles are generated on the screen due to an interference phenomenon of the laser according to coherence characteristics of the laser, thereby deteriorating picture quality by lowering contrast ratio and resolution.